try --scan all or --scan compac
your screenshot tells me that there seems to be another problem here.... if both cgminer and bfgminer have problems using your USB ports....
maybe a BIOS setting / driver update ?
I agree here. This feels far more like a windows/USB issue.
Along with trying zOU's suggestion - try cgminer with the --ndevs flag (cgminer --ndevs)
It should feed you output similar to the --scan option I believe.